If you want to check the accuracy by yourself, please use the white line detection function.

The measurement of the optional interval distance between the white lines is possible, when the output signal of the optional external trigger sensor (white line detection sensor) which is attached to the front of the vehicle is connected to the external signal input terminal (EXT. TRIG) in the front panel of the LC-7700 GPS Vehicle Speedometer.

Check the accuracy by comparing the actual interval distance which has been measured by the tape measure and interval distance which is measured by the LC-7700.